Expose: RFID-based location tracking

Internally code-named “expose”, we’re working on a new Hybris Labs experiment that is finally big and good enough to be blogged about. While it has been maturing for a few weeks now, it’s still in it’s infancy and many parts will prosper over time. What is it about? It’s all about using RFID readers to track the physical location of RFID tags (associated to opt-in colleagues) at our office in Munich. The proximity to the YaaS (hYbris As A Service) teams allowed us to create the complete architecture based on this platform and I am really thrilled to give you an idea about it with this blog post.

The system is currently still small, but also big enough to make technical sense. We have a setup of up to 5 RFID readers which are mapped against 5 locations (POIs, point of interest). These are two meeting rooms and 3 “areas” in the Hybris Munich office.

rfid

Before I go into detail, I’d love to cover the topic of privacy/security/etc. Are we saying that we would like to equip future customers with RFID labels to track them? No, we are not. This is an experiment, yielding a general-purpose location tracking API and means to process these events. RFID is a technology that we’ll likely use at events to generate these location-events in a very quick fashion. It brings the demos to life, as we’ll be able to consume many, many events over a short time. So keep that in mind.

The big picture

Just for the purpose of this post, I created the first architecture diagram. Let me step through the architecture, so you get a good understanding.

Expose Technical Architecture

At the very top, we have the RFID tags (sometimes called RFID labels) that have tiny micro-controllers and larger antennas around them. Those are the items we track. Each of these have unique IDs in their memory. They are passive, meaning that they don’t have a power supply of their own – they are powered by the energy that the RFID antennas in the next layer supply to them.  Up to 4 antennas can connect to a RFID reader, which is the “edge computing” element if you like. The RFID reader constantly scans for tags via the antennas and sends HTTPS POST requests to our back end services every 3 seconds. The data that these requests include is pretty basic: the reader’s MAC address and essentially a list of tags and the antenna (the port of the reader) that scanned the tag. Our RFID readers are from Impinj, a partner of SAP Hybris that we have used in the past for prototypes such as the Changing Room. Our main REST endpoint, the expose service,  is a node.js based cloudfoundry web app which is “YaaS-ified” by registering it as a YaaS service. This will later allow us on to setup security via OAuth2, metering, billing, etc… Another part that is currently purely fictional (as it does not yet exist) is the expose builder. The builder component will later allow a business user to administrate the setup. We’ve designed the whole system to be tenant-aware, which makes it easier to reuse for other events and purposes. Below the custom components (the expose service and builder module) you’ll find many core YaaS services that we are currently using: OAuth2 for getting access tokens to tenant-specific services such as documents (location history), customers (each RFID tag is associated to a customer object) and so on.

In a nutshell, we created a RFID-based location tracking system, which tries to be as technology-independent as possible. We’ve worked hard on the algorithms that try to determine the location of the RFID tags even though multiple readers scan the tags and send these requests with a few seconds offset to the back end service.  Our system is based on the rules of simplicity and honesty. We acknowledge that RFID has its shortcomings when it comes to tracking locations, for example we simply cannot scan tags that are “hidden” behind bodies. Therefore, the location that we emit will have an quality indication such as being

  • “fresh, insecure, just one-time scanned”
  • “safe, constantly scanned for several seconds” and
  • “stale, no more updates for this tag for some time”

Some Screenshots

Here are some early screenshots before beautification by our artists in residence (SNK).

zones

The zones UI (above) is a real-time view into the location tracking system. Updated via a socket.io connection, every second it shows all tags with associated customer accounts and their location state. Looks like I’ve been at Labs some time (therefore “safe” location), Agnieszka was “freshly scanned” at the cafe in the 4th floor and Ulf also just walked into the kleve meeting room.

map

Another view option is the map view. Terribly ugly right now, but technically already showing the data. We’ll change the UI soon and the concept behind the map – probably it will have the character of a heat map.

analytics_locations

Our first analytics UI will show the safe locations over the last 24 hours. It gives you an idea which areas are most frequented.

journey

Probably the roughest of the UIs (but hey, we have nothing to hide, have we?) is the journey UI. Per user, you can see the safe locations in a journey view (and again just the last 24h).

 What’s next?

While we already have a few UIs, the main focus at this point has to be on the technical aspects and to make the core RFID system run really well. We need to properly test the system with our colleagues and continue to find and fix bugs. But when it comes to big features that are currently in our heads, these are:

  • support for so-called “action readers” that will be tied to a location, but also to a specific action. In terms of an event, this might mean actions performed at the reception (new user signup) or the bar (2 cappuccinos). These actions are part of the journey elements and will probably be visualized in such a UI. This will also bring up interesting integrations with other YaaS core services such as the cart. As we already have customer accounts, this should be easy.
  • integration with SAP Hybris Profile to be able to do things like: “customer’s similar to you also visited these locations”, etc.
  •  once we’re stable enough: optimized UI’s – kiosk-style location maps etc. for the events. Also: a builder module for easy configuration of the system per tenant.

Please help us! Carry the RFID tags, check the UI’s provided to see if it makes sense, talk to us if you have questions!

Tell us what you think:

2 thoughts on “Expose: RFID-based location tracking

  1. Dominic Krasnopolski says:

    Hi guys,

    keep up the good work and really nice article, let me know when there’s a final version out there? May I participate maybe as well as a alpha/beta tester if you need some guys here? 😉

    Best regards
    Dominic

    • Sven Haiges says:

      Hi Dominic, thx for the great feedback. Right now this is an internal project, so we cannot give access for non-SAP employees. At some point, we will evaluate if it makes sense of open it up, e.g. open sourcing. But sadly, this is a bit in the future. Please keep on following the blog for updates!

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